JPH0756993B2 - ISDN terminal device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN terminal device such as a telephone and a terminal adapter that can be connected to an ISDN basic interface.

Prior Art FIG. 3 shows the configuration of a conventional ISDN terminal device. Third
In the figure, reference numeral 1 is an ISDN terminal device connected to a network 3 via a transmission line 2.

The ISDN terminal device 1 includes a layer 1 interface 4 for connecting to a transmission line 2, a layer 1 controller 5 for assembling and disassembling transmission frames, and a layer 2 controller 6 for controlling packet transmission on a D channel. IS composed of and
Consists of a DN interface system, a voice interface 8 for connecting the handset 7, etc., a serial input / output interface 10 for accommodating the personal computer 9, etc. by a serial transmission procedure, and a man-machine interface 13 for connecting a ten-key 11 and a display device 12. The existing interface system and the controller 14 that is a block that controls the ISDN call connection and that transfers control information to and from each block in the ISDN terminal device 1.

Then, the controller 14 passes the ISDN call connection control message to the assembly layer 2 control unit 6 by on-hooking the handset 7 and inputting the partner number from the ten-key pad 11. The layer 2 control unit 6 that has received the message transmits the message to the network 3 via the layer 1 control unit 5, the layer 1 interface 4, and the transmission path 2.
A data link is established between the network and the call connection control message so that the call connection control message can be transmitted to and received from the network 3. Further, in order to prevent a plurality of terminals from accessing the D channel at the same time, access competition control using the echo channel is performed.

Thus, even in the conventional ISDN terminal device described above, the functions of ISDN layers 1 to 3 conforming to the CCITT recommendation are fulfilled by the layer 1 interface 4, the layer 1 control unit 5, the layer 2 control unit 6, and the controller 14, Voice and data communication can be performed with other terminal devices via the network 3.

However, in the above conventional ISDN terminal device, even if there is an incoming call from another ISDN terminal during communication with another ISDN terminal via the network, the ISDN terminal in communication is the same user. -There was a problem that it was not possible to judge whether or not another ISDN terminal connected to the network interface in a multi-bus form answered the incoming call.

The present invention solves such conventional problems,
If there is an incoming call from another ISDN terminal via the network during communication, the ISDN terminal connected to the same ISDN terminal interface bus judges whether or not the incoming call is answered, and there is no response. Therefore, it is an object of the present invention to provide an excellent ISDN terminal device that stores the attribute and the partner number of the originator of the call.

Means for Solving the Problems In order to achieve the above object, the present invention provides an echo channel monitor unit for capturing a packet on an echo channel in which a signal channel from a terminal to a network is returned from the network as it is, and another communication channel It judges whether or not another ISDN terminal on the same basic interface bus has answered the call received from the ISDN terminal, and if there is no response, the attributes of the other side ISDN terminal that is the originator of the call and And a controller for storing the other party's number in the memory.

Effect According to the present invention having the above-described configuration, when the ISDN terminal device transmits a user protocol packet uniquely between the terminals on the D channel, this packet is returned as an echo channel as it is on the network side. By monitoring the above echo channel with the echo channel monitor, the same IS
Other ISDN terminal equipment connected to the DN basic interface bus responded, but if the controller identifies whether or not the ISDN terminal does not respond to the incoming call, the attribute of the other party and the other party number from which the call originated Can be stored in memory.

Embodiment FIG. 1 shows the structure of an embodiment of the present invention. twenty one
Is an ISDN terminal device connected to a network 23 via a transmission line 22.

The ISDN terminal device 21 includes a layer 1 interface 24 for connecting to a transmission line 22, a layer 1 control part 25 for assembling and disassembling a transmission frame, a layer 2 control part 26 for controlling packet transmission on a D channel, and an echo. An ISDN interface system composed of an ego channel monitor unit 27 that captures packets flowing through the channel and packets sent by other terminals, a voice interface 29 for connecting the handset 28, and a personal computer 30 are serialized. It is a block that realizes the service processing by the user protocol as well as the existing interface system that is configured by the serial input / output interface 31 and the man-machine interface 34 that connects the numeric keypad 32 and the display device 33 according to the transmission procedure and ISDN call connection control processing. ISDN
A controller 35 for exchanging control information with each block in the terminal device 21 is provided.

Fig. 2 shows an example of connection of ISDN terminal equipment.
The terminal devices 21a and 21b are connected to the network 23 via the same basic interface bus (transmission line) 22. 36 is a terminal accommodated in the network 23.

When the ISDN terminal 21a and the ISDN terminal 21b send / receive a call connection control message to / from the terminal 36 via the network 23, the message is sent from the terminal 36 to the D channel in the network direction (hereinafter, "uplink"). A packet is placed and a message packet flowing from the network 23 through the D channel in the direction of the terminal (hereinafter referred to as “downstream”) is captured. As for the downlink echo channel, the uplink D channel is returned as it is, and is used for access contention control of the uplink D channel.

Next, the operation of the above embodiment will be described. In the above embodiment, when the ISDN terminal 21a is communicating with the ISDN terminal 36 via the network 23 and a call is received from another ISDN terminal, the ISDN terminal 21a
Monitors the echo channel to determine whether another ISDN terminal on the same basic interface bus, eg, ISDN terminal 21b, answered the incoming call.

The determination as to whether or not a response has been made is made by using a timer (not shown) in the controller 35 to identify whether or not a response message has been sent from another ISDN terminal within a fixed time. As a result, when the ISDN terminal 21a determines that there is no response from the other ISDN terminal to the incoming call, the ISDN terminal 21a sets the attribute and the number of the other party ISDN terminal, which is the originator of the call received during communication, in the controller 35. In a memory (not shown).

As described above, according to the above-described embodiment, since the signal of the upstream D channel is returned as the echo channel on the network side, by providing the means for monitoring the echo channel, the same call can be received for the call received during the communication. It is possible to determine whether or not another ISDN terminal on the basic interface has responded, and if there is no response from the other ISDN terminal, store the attribute and the number of the other ISDN terminal that is the originator of the call. You can

As described above, the present invention is configured to capture the packet on the echo channel. Therefore, a call received during communication can be received by another ISDN on the same basic interface bus.
Only when the terminal does not respond, it is possible to store the partner attribute and the partner number from which the call originated.

[Brief description of drawings]

FIG. 1 is a block diagram of an ISDN terminal device according to an embodiment of the present invention, FIG. 2 is a schematic block diagram showing a connection state of the ISDN terminal device of FIG. 1, and FIG. 3 is a block diagram of a conventional ISDN terminal. is there. 21,21a, 21b …… ISDN terminal equipment, 22 …… Transmission line, 23 ……
Net 27: Echo channel monitor, 35: Controller.

Claims (1)

[Claims] 1. An echo channel monitor section for capturing a packet on an echo channel in which a signal channel from a terminal to the network is returned from the network as it is, and a call received from another ISDN terminal during communication, Whether or not another ISDN terminal on the same basic interface bus has responded is determined by monitoring the echo channel by the echo channel monitoring unit described above, and if no response is made, the ISDN terminal on the other side of the call originator An ISDN terminal device having a controller for storing attributes and a partner number in a memory.